Brake Drums
Grand Champion
Joined: May 2019
Posts: 5,172
Likes: 724
From: S.W. Indiana
For an update on the front rotors and rear drums. I finally got a set of front rotors I didn't have to turn, but the rear drums case (maybe in another thread) had to be turned after buying and sending back 3 times of different brands. They were not only out of round but out of balance. I got the drums turned but still the balance was off. To check the balance, I removed the wheels and drums on both sides and ran up the speed to 70 mph. Of course, the rear axle was on jack stands. No vibration without the wheels, tires, and drums or in the driveline. I put one drum on at a time and ran the speed up to 70 mph, both had vibrations. After doing a lot of research, I contacted a shop out on the East Coast that balances drums, the shipping and balancing cost was prohibitive. I ended up buying a bubble tire balancer. I would grind the heavy side down until I got the bubble to center. It is not a perfect balance, but it looks like I have to live with it. Another thing I did was buy balancing beads to put in the tires, which helped some more. One downside with the beads is, don't hammer the throttle from a stop or low speed, the beads won't get to where they need to be. I had to put beads in all 4 tires because I rotate the tires with every oil change. I think you have to get up to 35-45 mph for the beads to get to where they belong, and after that speed, you can hammer the throttle.
I was involved in using beads on over the road equipment once. We tried it on two rigs. One worked okay but I think it was in balance anyway. The other did fair, but rough roads would make it go out of balance and unless you drove on a smooth road for a bit, it stayed out of balance. We were hauling oil field equipment and the final result was they weren't worth the bother. VERY few smooth roads in the oil fields.
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Rookie
Joined: Aug 2015
Posts: 62
Likes: 5
I haven't hit a large enough chuck hole to throw mine out of balance traveling on the HWYs. Still yet the beads are better than the balance with wheel weights, not perfect, but almost there. Most likely I wouldn't notice it with a heavy load or pulling a loaded trailer, A trailer would buck the pickup enough to where I wouldn't notice the brums out of balance as they are. Anyway, this pickup feels every bump in the road. It is heavier for the gross weight of the 2500s with heavier springs and stiffer shocks. When I replaced the oem shocks with Bilsteins, the oem rubbers on the ends were worn out, beaten to death, but the oem shocks were as they should be. Bilsteins gave a lot smoother ride over bumps.
Record Breaker
Joined: Jan 2004
Posts: 1,433
Likes: 192
From: United States
I recently went through this on GMT400 with SF (semi-float) 14b
One drum from O'Reilly was completely out of round. There were also weights MIG welded on that were falling off. OEM removes material to balance rather than adding weight. Much more elegant.
I wound up returning to one OEM drum and one of the new drums was fine.
I also had to change brands of shoes because the first would grab. It seems these are particularly sensitive to radius of the shoe(s) vs drum ID. A different brand of shoes cured the grabby brakes altogether. This seems to be a known -- but still relatively uncommon -- problem with the SF 14b
One drum from O'Reilly was completely out of round. There were also weights MIG welded on that were falling off. OEM removes material to balance rather than adding weight. Much more elegant.
I wound up returning to one OEM drum and one of the new drums was fine.
I also had to change brands of shoes because the first would grab. It seems these are particularly sensitive to radius of the shoe(s) vs drum ID. A different brand of shoes cured the grabby brakes altogether. This seems to be a known -- but still relatively uncommon -- problem with the SF 14b
